This invention is a tool for automotive engine work, and more specifically a tool for removal and reinstallation of engine valve springs, retainers, and keepers.
An automotive engine "valve job" involves removal of the valve cover and cylinder head, followed by disassembly and removal of each valve from the cylinder head for replacement or repair. The valves are held in place in the cylinder head, each by a compression spring acting on the valve stem keeping it tightly closed. A dish-shaped retainer centered on top of the valve spring has a frusto-conical inner ramp surface which engages a pair of frusto-conical "keepers", forcing them into positive locking engagement with the valve stem. The two keepers are halves of a split ring, together forming a frusto-conical ring to surround and engage the inner ramp of the retainer. The inner surfaces of the keepers together form one or more circumferential keys to engage corresponding circumferential keyways near the top of the valve stem. The conical inner surface of the retainer engages the conical outer surface of the keepers to force them into locking engagement with the valve stem.
To disassemble and remove a valve, it is first necessary to further compress the valve spring, move the retainer out of engagement with the keepers, remove the keepers which are now loose, remove the retainer and spring (which are now free), then slide the valve stem (which is now free) out through the underside of the cylinder head.
In the prior art, the procedure just described is performed by using a C-clamp or the like to compress the valve spring, then using one's fingers or long nose pliers to remove the keepers. Another expedient is the use of a lever having a notch at its end to straddle the valve stem, the fulcrum of the lever being anchored to a rocker arm stud. The lever is pivoted about the rocker arm stud to thereby compress the valve spring and permit manual removal of the keepers. These devices are the prior art that I know of.